Regression (r10675): snapping to node targets fails

Steps to reproduce:
1) launch inkscape with default new prefs
2) open attached drawing
3) try to snap e.g. a guide to one of cusp nodes of the 'cross' within the dotted frame

Expected result:
The guide can be snapped to any of the cusp nodes

Actual result:
No snap targets are detected

Also affects all path tools and the node tool, affects other node snap targets (path, intersection, smooth, midpoint of line).
Snapping nodes to other snap targets (grid, guides, midpoint, rotation center) works correctly.

I fail to consistently reproduce this in a new drawing - at best the node snapping behavior in r10675 seems erratic to me (it does not seem related to the known issues with path intersections). The objects in the attached document originate (via copy & paste) from a custom 'icons.svg' file (WIP).

Workaround: apparently, with this document, snapping to node targets works if changing
'Document properties > Snap to Objects' to '[x] Always snap'
(which I'd rather not do ;) )

Not reproduced with Inkscape 0.48+devel r10672
Reproduced with Inkscape 0.48+devel r10675
on Mac OS X 10.5.8 (i386)